Over the past several years, environmental and ecological problems associated with oil-base hot forging lubricants have lead to a serious need for more desirable and workable water-base lubricating compositions for use in hot forgings. Past attempts directed to water-base compositions have involved the use of materials such as graphite, clay minerals, iron oxide, and molybdenum disulfide. These attempts, however, have in many instances not been fully satisfactory for any one of numerous reasons. One of such reasons is the inability to properly lubricate the forging die under actual operating procedures involving very hot or elevated temperature conditions. Another reason is that the presence of water in the composition often times does not adequately wet the metal surface involved. Still another reason is the improper working of some prior water-base lubricants at elevated temperatures. Thus, there has been a need in the field for a water-base lubricant which will provide improved lubrication and wetting of a hot forging die at elevated temperatures.
The state of the art is indicated by the following cited references. U.S. Pat. Nos.: 3,983,042 to Jain et al; 2,937,993 to Pattenden et al; 2,940,930 to Pattenden et al; 2,898,296 to Pattenden et al; 3,985,662 to Campbell et al; 2,349,817 to Farmington et al; 3,929,651 to Murray et al; 3,507,791 to Teeter et al; 3,375,193 to Ruzza et al; 3,313,729 to Glasson; 2,921,879 to Kubie; 2,735,864 to Hodson Sr. et al; 4,401,579 to Kratzer; 4,454,050 to Bertell; 4,409,113 to Bertell; U.K. Application Publication No. 2,046,298A; British Pat. Nos. 721,255; 856,924; and 995,708. Bertell U.S. Pat. No. 4,450,050 discloses a lubricant composition which requires a combination of an aromatic polycarboxylic acid (phthalic acid) and an aliphatic polycarboxylic acid (adipic acid). Bertell teaches away from using anything other than such combinations.
Accordingly, a primary object of this invention is to provide a new and unique water-base lubricant composition which is highly useful as a lubricant material in elevated temperature metal forming operations.
Another object of the present invention is to provide such a composition wherein wetting temperatures on the metal forging surfaces are significantly higher, at comparable solid levels, than prior water-base lubricant compositions for hot metal forming.
Another object of the invention is to provide a new water-base lubricant composition which would provide reduced press loading during the metal forming operation.
Another object of the invention is to provide a new water-base lubricant composition which permits enhanced and superior metal movement during the elevated temperature metal forming operation.
Other objects, features, and advantages of the present invention will become apparent from the subsequent description and the appended claims.